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Just wanted to doublecheck, im about to wire a Q45 AFM (well 2 actually through an Apexi SAFC II) and since PaulR33s site is down or under construction its hard to find the correct info.

Heres what i've got so far:

Q45 AFM

3 wires marked BDE

B - Signal

D - Ground

E - 12v Power

RB25DET Series 1 AFM plug

4 wires

1 - None

2 - Signal

3 - 12v Ground

4 - Signal ground

5 - 12v Power

This gives:

B -> 2

D -> 3&4

E -> 5

As far as i've read im supposed to unite the Ground (3) and Signal ground (4) and connect it to the one Ground (D) coming out of the Q45 AFM, is this correct?

Though im using the Apexi SAFC II to be able to use 2 AFMs and this thread doesnt cover that it still feels good to know that the basics around one operation before continuing with the next one, which i think/hope i've got covered.

/Dave

try temporary upload here;

http://www.paulr33.com/airflow-meter-wiring.html

the URL will change later so dont bookmark it etc, but until i fix, you can use that page

let me know if you are after a different page

Thanks Paul, appreciate it!

Also if someone could confirm that the RB25 Ground & Signal Ground can be united and connected to Ground on the Q45 AFM it would take some more problems off my mind.

tried this, but my Power-fc isnt set up for Q45 afm's.

so it just would NOT run.

could choose GTR32, gtr33, apexi power intake, rb25, vg30

Im going to have to sell my Q45 afm's, awaiting some Z32 (vg30) afm's now

hi tangles

ive checked the VH41 / Q45 AFM ramp in the RB25DET powerfc and its not that much different to the Z32

the Q45 has a touch higher airflow values in the higher range, sub 3v but below that it's pretty close

i would expect your car to idle with Q45 AFM's even if you can't select them, if anything it should be a bit grumpy and maybe blow a bit of smoke at the worst case. with my R33 GTST and stock AFM (s2 AFM) im able to choose VH41 / Q45 from my AFM menu while the engine is runing and it keeps idling, the idle drops a note but it continues to run correctly (i would expect it to).

so i expect that something else is wrong, mangled wiring, incorect wiring, dead AFM etc

you could check them both out at ETC, SENSOR SW CHECK and look at AF-1 and AF-2

they should be pretty close at key ON (but not start) and shouldnt have a black highlighted background on the sensor name

if you have access to datalogit you can edit the AFM RAMP (not visible on hand controller) to make any of the AFMs on your menu match the Q45 ramp set by apexi (takes about 2 minutes). but it is a shame they didnt program the GTR RB26 tune with Q45 on the stock menu. there is bugger all difference between BNR32/BCNR33 so why bother putting them as seperate options on the AFM menu

Connected everything up and so far so good, though i still have to mount the gearbox and startermotor before trying an actual start up.

Clicked around in the Apexi SAFC II menus and found where to set what AFM im using but they're simply a figure01, 02 etc etc but i dont actually know what to try out when im running the Q45s or if this is actually for the output into the ECU which in that case would be 01 for a stock R33 GTST sensor cable.

Also dont know if i have to actually have to set that im using 2 inputs or if it gets registered as soon as it gets a value from the second AFM cable.

Monitoring the AFMs in the SAFC they gave ~0.248v and ~0.250v when key is in 'ON' position.

Found where to set the output to AVG (average) so that part is cleared.

  • 2 weeks later...

Hi Paul,

I'm running an R33 series 2 RB25det with a VG30 AFM on PFC, I've got my hands on a VH41 unit and was wondering is the wiring the same for the VG30 and VH41 AFM's or do I need to re-wire to match? I cant seem to get your earlier posted wiring diagram.

Cheers! :(

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